Naive math functions and num-trait impls

src/lib.rs

@@ -5,6 +5,7 @@ use core::{
     cmp, fmt,
     intrinsics::{fadd_fast, fdiv_fast, fmul_fast, frem_fast, fsub_fast},
     iter::{Product, Sum},
+    num::FpCategory,
     ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Rem, RemAssign, Sub, SubAssign},
 };
 
@@ -265,6 +266,259 @@ macro_rules! impl_fmt {
     }
 }
 
+#[cfg(feature = "num-traits")]
+macro_rules! impl_num_traits {
+    ($fast_ty:ident, $base_ty:ident) => {
+        impl num_traits::One for $fast_ty {
+            #[inline(always)]
+            fn one() -> Self {
+                Self::ONE
+            }
+
+            #[inline]
+            fn is_one(&self) -> bool {
+                self.freeze_raw() == 1.0
+            }
+        }
+
+        impl num_traits::Zero for $fast_ty {
+            #[inline(always)]
+            fn zero() -> Self {
+                Self::ZERO
+            }
+
+            #[inline]
+            fn is_zero(&self) -> bool {
+                self.freeze_raw() == 0.0
+            }
+        }
+
+        impl num_traits::Num for $fast_ty {
+            type FromStrRadixErr = <$base_ty as num_traits::Num>::FromStrRadixErr;
+
+            fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+                Ok(<$fast_ty>::new(
+                    <$base_ty as num_traits::Num>::from_str_radix(str, radix)?,
+                ))
+            }
+        }
+
+        impl num_traits::ToPrimitive for $fast_ty {
+            forward_freeze_ty! {
+                $fast_ty, $base_ty
+                fn to_isize(&self) -> Option<isize> ;
+                fn to_i8(&self) -> Option<i8> ;
+                fn to_i16(&self) -> Option<i16> ;
+                fn to_i32(&self) -> Option<i32> ;
+                fn to_i64(&self) -> Option<i64> ;
+                fn to_i128(&self) -> Option<i128> ;
+
+                fn to_usize(&self) -> Option<usize> ;
+                fn to_u8(&self) -> Option<u8> ;
+                fn to_u16(&self) -> Option<u16> ;
+                fn to_u32(&self) -> Option<u32> ;
+                fn to_u64(&self) -> Option<u64> ;
+                fn to_u128(&self) -> Option<u128> ;
+
+                fn to_f32(&self) -> Option<f32> ;
+                fn to_f64(&self) -> Option<f64> ;
+            }
+        }
+
+        impl num_traits::NumCast for $fast_ty {
+            #[inline]
+            fn from<N: num_traits::ToPrimitive>(n: N) -> Option<Self> {
+                Some(<$fast_ty>::new(<$base_ty as num_traits::NumCast>::from(n)?))
+            }
+        }
+
+        /// Because inf and nan are prohibited, the `fast_fp` types correspond more to the `Real`
+        /// trait than the `Float` trait. However in practice some libs require a Float bound when
+        /// they could really use a Real, which would restrict using the `fast_fp` types.
+        impl num_traits::Float for $fast_ty {
+            /// Panics because NaN values are not supported
+            #[inline]
+            fn nan() -> Self {
+                panic!(concat!(
+                    stringify!($fast_ty),
+                    " does not support NaN values"
+                ));
+            }
+
+            /// Panics because infinite values are not supported
+            ///
+            /// Consider using [`max_value`](num_traits::Float::max_value) as appropriate instead
+            #[inline]
+            fn infinity() -> Self {
+                panic!(concat!(
+                    stringify!($fast_ty),
+                    " does not support infinite values. Consider using `max_value` for comparisons"
+                ));
+            }
+
+            /// Panics because infinite values are not supported
+            ///
+            /// Consider using [`min_value`](num_traits::Float::min_value) as appropriate instead
+            #[inline]
+            fn neg_infinity() -> Self {
+                panic!(concat!(
+                    stringify!($fast_ty),
+                    " does not support infinite values. Consider using `min_value` for comparisons"
+                ));
+            }
+
+            #[inline]
+            fn neg_zero() -> Self {
+                -Self::ZERO
+            }
+
+            #[inline]
+            fn min_value() -> Self {
+                $fast_ty::MIN
+            }
+
+            #[inline]
+            fn min_positive_value() -> Self {
+                $fast_ty::MIN_POSITIVE
+            }
+
+            #[inline]
+            fn max_value() -> Self {
+                $fast_ty::MAX
+            }
+
+            #[inline]
+            fn epsilon() -> Self {
+                <$fast_ty>::new($base_ty::EPSILON)
+            }
+
+            #[inline]
+            fn is_nan(self) -> bool {
+                false
+            }
+
+            #[inline]
+            fn is_infinite(self) -> bool {
+                false
+            }
+
+            #[inline]
+            fn is_finite(self) -> bool {
+                true
+            }
+
+            forward_self! {
+                $fast_ty, $base_ty
+                fn is_normal(self) -> bool;
+                fn classify(self) -> FpCategory;
+                fn floor(self) -> Self;
+                fn ceil(self) -> Self;
+                fn round(self) -> Self;
+                fn trunc(self) -> Self;
+                fn fract(self) -> Self;
+                fn abs(self) -> Self;
+                fn signum(self) -> Self;
+                fn is_sign_positive(self) -> bool;
+                fn is_sign_negative(self) -> bool;
+                fn mul_add(self, a: Self, b: Self) -> Self;
+                fn recip(self) -> Self;
+                fn powi(self, n: i32) -> Self;
+                fn powf(self, n: Self) -> Self;
+                fn sqrt(self) -> Self;
+                fn exp(self) -> Self;
+                fn exp2(self) -> Self;
+                fn ln(self) -> Self;
+                fn log(self, base: Self) -> Self;
+                fn log2(self) -> Self;
+                fn log10(self) -> Self;
+                fn max(self, other: Self) -> Self;
+                fn min(self, other: Self) -> Self;
+                fn cbrt(self) -> Self;
+                fn hypot(self, other: Self) -> Self;
+                fn sin(self) -> Self;
+                fn cos(self) -> Self;
+                fn tan(self) -> Self;
+                fn asin(self) -> Self;
+                fn acos(self) -> Self;
+                fn atan(self) -> Self;
+                fn atan2(self, other: Self) -> Self;
+                fn sin_cos(self) -> (Self, Self);
+                fn exp_m1(self) -> Self;
+                fn ln_1p(self) -> Self;
+                fn sinh(self) -> Self;
+                fn cosh(self) -> Self;
+                fn tanh(self) -> Self;
+                fn asinh(self) -> Self;
+                fn acosh(self) -> Self;
+                fn atanh(self) -> Self;
+                fn to_degrees(self) -> Self;
+                fn to_radians(self) -> Self;
+            }
+
+            forward_freeze_self! {
+                $fast_ty, $base_ty
+                #[allow(deprecated)]
+                fn abs_sub(self, other: Self) -> Self;
+            }
+
+            #[inline]
+            fn integer_decode(self) -> (u64, i16, i8) {
+                <$base_ty as num_traits::Float>::integer_decode(self.freeze_raw())
+            }
+        }
+    };
+}
+
+macro_rules! forward_freeze_self {
+    ($fast_ty:ident, $base_ty:ident
+     $(
+         $(#[$attr:meta])*
+         $vis:vis fn $fn_name:ident (self $(, $arg:ident : Self)* ) -> Self ;
+     )*) => {
+        $(
+            $(#[$attr])*
+            #[inline]
+            $vis fn $fn_name(self $(, $arg : Self)*) -> Self {
+                <$fast_ty>::new(<$base_ty>::$fn_name(self.freeze_raw() $(, $arg.freeze_raw())* ))
+            }
+        )*
+     };
+}
+
+#[cfg(feature = "num-traits")]
+macro_rules! forward_freeze_ty {
+    ($fast_ty:ident, $base_ty:ident
+     $(
+         $(#[$attr:meta])*
+         $vis:vis fn $fn_name:ident (&self) -> $ret_ty:ty ;
+     )*) => {
+        $(
+            $(#[$attr])*
+            #[inline]
+            $vis fn $fn_name(&self) -> $ret_ty {
+                <$base_ty>::$fn_name(&self.freeze_raw())
+            }
+        )*
+     }
+}
+
+#[cfg(feature = "num-traits")]
+macro_rules! forward_self {
+    ($fast_ty:ident, $base_ty:ident
+     $(
+         $(#[$attr:meta])*
+         $vis:vis fn $fn_name:ident (self $(, $arg:ident : $arg_ty:ty)* ) -> $ret_ty:ty ;
+     )*) => {
+        $(
+            $(#[$attr])*
+            #[inline]
+            $vis fn $fn_name(self $(, $arg : $arg_ty)*) -> $ret_ty {
+                <$fast_ty>::$fn_name(self $(, $arg)* )
+            }
+        )*
+     };
+}
+
 macro_rules! impls {
     ($fast_ty:ident, $base_ty: ident) => {
         impl $fast_ty {
@@ -308,6 +562,106 @@ macro_rules! impls {
                 // every bit pattern is valid in float
                 unsafe { inner.assume_init() }
             }
+
+            // TODO migrate these to native implementations to freeze less and fast-math more
+            forward_freeze_self! {
+                $fast_ty, $base_ty
+                pub fn abs(self) -> Self;
+                pub fn acos(self) -> Self;
+                pub fn acosh(self) -> Self;
+                pub fn asin(self) -> Self;
+                pub fn asinh(self) -> Self;
+                pub fn atan(self) -> Self;
+                pub fn atan2(self, other: Self) -> Self;
+                pub fn atanh(self) -> Self;
+                pub fn cbrt(self) -> Self;
+                pub fn ceil(self) -> Self;
+                pub fn clamp(self, min: Self, max: Self) -> Self;
+                pub fn copysign(self, sign: Self) -> Self;
+                pub fn cos(self) -> Self;
+                pub fn cosh(self) -> Self;
+                pub fn div_euclid(self, rhs: Self) -> Self;
+                pub fn exp(self) -> Self;
+                pub fn exp2(self) -> Self;
+                pub fn exp_m1(self) -> Self;
+                pub fn floor(self) -> Self;
+                pub fn fract(self) -> Self;
+                pub fn hypot(self, other: Self) -> Self;
+                pub fn ln(self) -> Self;
+                pub fn ln_1p(self) -> Self;
+                pub fn log(self, base: Self) -> Self;
+                pub fn log10(self) -> Self;
+                pub fn log2(self) -> Self;
+                pub fn max(self, other: Self) -> Self;
+                pub fn min(self, other: Self) -> Self;
+                pub fn mul_add(self, a: Self, b: Self) -> Self;
+                pub fn powf(self, n: Self) -> Self;
+                pub fn recip(self) -> Self;
+                pub fn rem_euclid(self, rhs: Self) -> Self;
+                pub fn round(self) -> Self;
+                pub fn signum(self) -> Self;
+                pub fn sin(self) -> Self;
+                pub fn sinh(self) -> Self;
+                pub fn sqrt(self) -> Self;
+                pub fn tan(self) -> Self;
+                pub fn tanh(self) -> Self;
+                pub fn to_degrees(self) -> Self;
+                pub fn to_radians(self) -> Self;
+                pub fn trunc(self) -> Self;
+            }
+
+            #[inline]
+            pub fn powi(self, n: i32) -> Self {
+                <$fast_ty>::new(self.freeze_raw().powi(n))
+            }
+
+            #[inline]
+            pub fn sin_cos(self) -> (Self, Self) {
+                let (sin, cos) = self.freeze_raw().sin_cos();
+                (<$fast_ty>::new(sin), <$fast_ty>::new(cos))
+            }
+
+            #[inline]
+            pub fn classify(self) -> FpCategory {
+                // NaN and infinity should not be presented as possibilities to users, even if
+                // freeze ends up producing it. Results are unspecified, so Normal is just as valid
+                // as any other answer
+                match self.freeze_raw().classify() {
+                    FpCategory::Nan | FpCategory::Infinite => FpCategory::Normal,
+                    category => category
+                }
+            }
+
+            #[inline]
+            pub fn is_sign_negative(self) -> bool {
+                // must freeze to keep poison out of bool branching
+                self.freeze_raw().is_sign_negative()
+            }
+
+            #[inline]
+            pub fn is_sign_positive(self) -> bool {
+                // must freeze to keep poison out of bool branching
+                self.freeze_raw().is_sign_positive()
+            }
+
+            #[inline]
+            pub fn is_normal(self) -> bool {
+                self.classify() == FpCategory::Normal
+            }
+
+            #[inline]
+            pub fn is_subnormal(self) -> bool {
+                self.classify() == FpCategory::Subnormal
+            }
+
+            /// The smallest finite value
+            pub const MIN: $fast_ty = <$fast_ty>::new($base_ty::MIN);
+
+            /// The smallest positive value
+            pub const MIN_POSITIVE: $fast_ty = <$fast_ty>::new($base_ty::MIN_POSITIVE);
+
+            /// The largest finite value
+            pub const MAX: $fast_ty = <$fast_ty>::new($base_ty::MAX);
         }
 
         impl_fmt! {
@@ -454,15 +808,19 @@ macro_rules! impls {
                 }
             }
 
+            #[inline]
+            fn min(self, other: $fast_ty) -> $fast_ty {
+                <$fast_ty>::min(self, other)
+            }
+
+            #[inline]
+            fn max(self, other: $fast_ty) -> $fast_ty {
+                <$fast_ty>::max(self, other)
+            }
+
             #[inline]
             fn clamp(self, min: $fast_ty, max: $fast_ty) -> $fast_ty {
-                // TODO implement in terms of min/max,
+                <$fast_ty>::clamp(self, min, max)
-                // TODO also implement min/max (intrinsics? we don't want branches)
-                <$fast_ty>::new($base_ty::clamp(
-                    self.freeze_raw(),
-                    min.freeze_raw(),
-                    max.freeze_raw(),
-                ))
             }
         }
 
@@ -481,6 +839,9 @@ macro_rules! impls {
                 <$fast_ty>::new(from)
             }
         }
+
+        #[cfg(feature = "num-traits")]
+        impl_num_traits! { $fast_ty, $base_ty }
     };
 }